Field of the Invention
This invention relates to a novel lithium-doped gamma-alumina supported cobalt-molybdenum catalyst and to a process for converting synthesis gas to a mixture of lower aliphatic alcohols characterized by containing a substantial proportion of alcohols having from 2 to 6 carbon atoms.
Lower aliphatic alcohols have been proposed as fuel extenders for gasoline for fueling internal combustion engines. Certain mixtures of lower aliphatic alcohols for use in motor fuels have the EPA approval and are currently being marketed in the United States. The lower aliphatic alcohols can be produced from a domestically available non-petroleum source, and their use in fuels serves to lessen dependence on imported crude oil or petroleum products.
Hydrogen and carbon monoxide, or a synthesis gas mixture of same, can be reacted to form lower aliphatic alcohols. A synthesis gas feedstream can be produced from non-petroleum sources, such as coal, biomass or other hydrocarbonaceous materials. The synthesis gas mixture can be produced in a partial oxidation reaction of the hydrocarbonaceous material as, for example, in a coal gasification process.
Numerous catalytic processes have been studied in attempts to provide a viable process for the production of aliphatic alcohols from synthesis gas or from a mixture of hydrogen and carbon monoxide. Earlier developments were primarily directed to the production of methanol. In contrast to this, the present process is directed to a method for producing an alcohol mixture containing a substantial amount of aliphatic alcohols having from 2 to 6 carbon atoms.
A major problem with the synthesis gas to alcohol conversion process is the occurrence of competing reactions constantly taking place on the surface of the catalyst. Thus, even when the desired product is formed on the catalyst, some of this product may undergo further reactions with adverse effects on the yield of the desired product. It is evident that if some means could be provided for reducing or minimizing competing reactions on the catalyst surface, then improved yields of the desired product might be obtained.